Problems encountered with such reflectors are the contrast of the light that is sometimes too high at the limit or edge of the region to illuminate and/or the light is not uniform near the cut-off direction, especially when a plurality of punctual light sources is used. As a consequence the lighting effects may be unpleasant and/or non aesthetic, especially problematic for Accent Lighting or Spot Lighting applications.
It is known to use some lenses as accessories, to smooth the light beam near the cut-off direction, those lenses being typically provided at the outlet of the reflector.
For example U.S. Pat. No. 4,506,316, U.S. Pat. No. 5,199,787 and U.S. Pat. No. 7,040,789 disclosed disk-shaped lenses provided with an annular portion having a plurality of tapered optical elements to deviate the rays passing proximate the light cut-off directions.
However, the limits of the region to be illuminated may be not sufficiently controlled when using this technique and the lighting efficiency may be not optimized.